The provision of a supply of air at positive pressure to the airways of a patient is well established as part of treatment of a range of respiratory conditions. Devices used for this treatment include a source of air at positive pressure, some form of air delivery conduit and some form of mask or “patient interface” as it is sometimes more generally described.
Patient interfaces, such as a nasal mask assembly, for use with Continuous Positive Airway Pressure Devices (CPAP), flow generators or blowers in the treatment of sleep disordered breathing (SDB) typically include a soft-patient contacting portion, such as a cushion, and a rigid shell or frame. In use, the patient interface is held in a sealing position by headgear so as to enable a supply of air at positive pressure to be delivered to the patient's airways.
Factors in the efficacy of therapy and compliance of patients with therapy are:                mask comfort;        sealing;        stability (e.g. aids in sealing);        fit; and        ease of use.        
Another problem encountered in the prior art is manufacturability, particularly when manufactured on a large scale.
While there are a large number of patient interfaces designed for adults, there are relatively few designed to suit infants and children. These include the ResMed Infant Bubble mask, the masks described in International Patent Applications WO/2001/032250 (Sullivan & Wilkie assigned to the Australian Centre for Advanced Medicine Technology Ltd); WO/2004/073777 (Ging, Kwok et al. assigned to ResMed Ltd); WO/2007/045023 (Kwok, Slvarajan et al., assigned to ResMed Ltd) and WO/2007/041786 (Selvarajan, Kwok et al assigned to ResMed Ltd).
Infants present a different series of challenges for the mask designer beyond simply making the mask smaller. The faces of young children are not only smaller, but a different shape to adults. Children's faces and skulls are soft and not fully formed, and there is a risk that excessive forces could lead to negative consequences. Furthermore, young children cannot articulate reasons why should they become distressed and rely on adults to fit their masks.